Socio-spatial segregation is an important research topic in urban social geography. Most of the research pays more attention to the residential differentiation and segregation of different groups and proposes that geographical segregation exacerbates the social isolation between disadvantaged groups and other social classes. However, most existing research ignores the spatial differentiation that people suffer from in their daily lives and discusses little about segregation in nonresidential spaces. In the context of increasing mobility, even residents living in the same neighborhood face different degrees of segregation due to differences in the choice of venues, resulting in a lower likelihood of social interaction. Therefore, recent research suggests that it is necessary to pay attention to the differentiation and segregation faced by residents in daily activity spaces and to understand social space from a more comprehensive perspective. However, due to the constraints of data and methods, only a few prior studies have quantitatively measured the activity space segregation of residents living in the same neighborhoods. In particular, there is currently no research focusing on whether policy and planning can effectively reduce activity space segregation. This study intends to solve the problem of socio-spatial segregation in the daily lives of different residents in the same neighborhood through the measurement of activity space. Taking the suburbs of Shanghai as an example, this study analyzes the degree of overlap between residents and other social groups in activity spaces, calculates the "shared activity space" index among individuals, and calculates an individual-scale activity space differentiation index and isolation index on this basis to measure the isolation of different income groups within the community. This indicates that there is indeed segregation between different groups, and the degree of segregation is influenced by individual socio-economic attributes, the mix of residential groups, and the spatial distribution of urban facilities. Living in a neighborhood with high population density, a high social mix, a good community business configuration, and sufficient public space can indeed increase the sharing of residents' activity spaces, while nearby shopping centers will cause isolated activity spaces.